1. Field of the Invention
The present invention relates to apparatus and process for the continuous preparation and separation of lithium by the electrolysis of lithium chloride contained in a mixture of molten salts.
2. Description of the Prior Art
The preparation of lithium by the electrolysis of lithium chloride contained in a mixture of molten salts based upon lithium chloride and at least one alkali and/or alkaline earth metal chloride, is known to this art and has been described, for example, in connection with processes for the preparation of silane, in U.S. Pat. Nos. 3,078,218 and 3,163,590. These particular patented processes are characterized by at least one of the following attributes:
(1) The process is carried out semi-continuously, i.e., the electrolytic cell is charged with an electrolyzable mixture and the electrolysis of the desired amount of lithium chloride is conducted in such mixture, after which a fresh charge of lithium chloride is added to the remaining mixture; and
(2) Complex and delicate apparatus is required, on the one hand to separate, in the electrolyzer itself, the lithium obtained from the mixture of molten salts, and, on the other hand, to prevent the recombination of the gaseous chlorine produced with the lithium; thus, for example, the atmosphere in the cell above the layer of lithium is very carefully controlled and a diaphragm is placed in the bath between the anode and the cathode.